The thermostats will not work without a C-wire. Our control panel had to upgraded in order to make the connections. It was much more complex and expensive than I expected.
I’ve never owned a smart thermostat before, but I don’t see my self trying out a different one. This one is pretty sweet in my opinion.
The availability of options when it comes to scheduling, and in home setting is great. And switch from my old Mercury thermostat was an easy thing to do for also being my first time, the instructions were easy to understand. I would definitely recommend.